Who are Rabia and Safa in the novel, Amal Unbound?

Rabia is Amal’s four-year-old sister, and Safa is Amal’s three-year-old sister. They frequently fight with each other, often over dolls. Because Rabia and Safa share matching black curls and dimples, people often mistake them for twins. They both love Amal and depend on her while Mehnaz recovers from Lubna’s birth.